A new concept for a millimeter-wave amplifier that uses circuit, waveguide,
and spatial power combining is demonstrated. The passive array has a free-
space-to-microstrip insertion loss below -1.5 dB from 30 to 44 GHz, Small-s
ignal measurements of the active array reveal an average gain of 5 dB from
41 to 46 GHz and a maximum gain of 6.4 dB at 45.6 GHz, Large-signal measure
ments reveal a linear power gain of 2 dB and an output power of 23.7 dBm at
the l-dB compression point at 44 GHz.